Osteochondral defects in adult knees are a common clinical finding. The limited reparative potential of such osteochondral defects has motivated numerous studies aimed at finding improved methods of treatment. Currently used procedures such as abrasion arthroplasty and microfracture, autologous chondrocyte implantation, osteochondral autografts and allografts, and partial or total joint arthroplasties have yielded varying levels of success. All current techniques suffer from deficiencies, such as donor site morbidity, limited tissue supply, immunorejection, potential transmission of pathogens, and implant loosening. Because of these issues, the development of a tissue-engineered osteochondral composite has attracted interest.
The creation of tissue-engineered osteochondral composites requires living chondrogenic cells. Commonly used cells in tissue engineering are mesenchymal stem cells (MSCs) which are multipotent progenitor cells that can undergo differentiation into other cell types, including chondrocytes. In addition, tissue-engineered osteochondral composites require synthetic substitutes for the cartilaginous extracellular matrix and subchondral support material.
The efficacy of existing tissue-engineered osteochondral composites has been hampered by the difficulty of bonding the softer material used for artificial cartilaginous extracellular matrix to the harder material used for the subchondral support material. In existing tissue-engineered osteochondral composites, the cartilaginous matrix material has been bonded to a porous ceramic or metal support material using sutures or surgical glue. To date, existing tissue-engineered osteochondral composites have had limited success due to problems associated with the separation of the artificial cartilaginous extracellular matrix from the underlying subchondral support.
Therefore, there is a need to provide a new and improved osteochondral composite and a method for fabrication thereof such that a strong and durable bond is established between the artificial cartilaginous extracellular matrix and the underlying subchondral support.